Many electronic devices (e.g., mobile phones, laptops, tablets, smartwatches, etc.) are powered by secondary cells (e.g., rechargeable batteries, similar energy storage devices, etc.) that need to be charged at regular intervals by power supply devices (also known as chargers, battery chargers, or rechargers).
Generally, the conventional electronic device charging process requires physical connections (such as a wire or a point of contact) between the secondary cell of the electronic device and a stationary or immobile charger. Conventional chargers include, but are not limited to, a direct current (DC) power adapter, a wireless charging plate or bowl apparatus, an alternating current (AC) adapter, an AC/DC adapter, and an AC/DC converter.
In addition, inductive charging (also known as wireless charging) can be used to charge a secondary cell of an electronic device. Generally, wireless charging refers to use of an electromagnetic field to transfer energy between a secondary cell of an electronic device and a charger capable of inductive charging.
Existing wireless charging solutions offer potential advantages (such as greater convenience, durability, and increased protection from corrosion) when compared to more conventional charging solutions that require physical connections. Nevertheless, the shrinking sizes, the increasing mobility, and the increasing performance requirements of electronic devices are creating challenges for semiconductor packages that are part of wireless charging solutions. For example, there is an increased demand for semiconductor packages that assist with on-the-go wireless charging of a secondary cell—i.e., wireless charging that does not require a user to remain at a stationary location while the device is being charged. Further, existing semiconductor packages that are part of wireless charging solutions might charge secondary cells slower, might be more expensive to manufacture, and might be more complex to design than semiconductor packages of more conventional charging solutions.
Some currently existing wireless charging solutions are embodied as one or more objects that are carried around by a user—for example, a wireless charging device encased in a single housing is carried in a user's hand. Carrying such wireless charging solutions around can be inconvenient for a user.
Other currently existing wireless charging solutions require energy used for charging to be harvested from the user of the wireless charging solution. Such energy includes, but is not limited to, vibrational energy, thermal energy, and mechanical energy. There are some disadvantages associated with using energy harvested from a user to wirelessly charge a device—e.g., unpredictable power yield; low power yield; and heavy, rigid, or awkward human energy harvesting devices that can lead to relatively high metabolic energy costs and correspondingly low energy conversion efficiency or impairment of normal physical activity for a user. Further, some wireless charging solutions used in wearables can include semiconductor packages that are suboptimal for size-critical applications.